There have been used in many applications tape recorders of the cartridge type in which by insertion of a cartridge holding a magnetic tape, signals are recorded on the magnetic tape in the cartridge, and the recorded signals are reproduced. In such cartridge-type tape recorders, during insertion of the cartridge, the cartridge has to be properly located or positioned in a recording and reproducing position.
FIG. 9 shows one example of cartridge positioning mechanisms used in the conventional tape recorders. In FIG. 9, a cartridge 1 holding a magnetic tape includes at its bottom a plate 2 having a notch 2a. A shaft 4 has a roller 3 fixedly mounted thereon urged upwardly by a leaf spring 5 so as to press the roller 3 against the peripheral edge of the notch 2a. As such, the cartridge 1 is pressed against an upper reference surface (not shown) disposed horizontally and a right-hand reference surface (not shown) disposed vertically, thereby effecting the positioning of the cartridge 1.
As disclosed in Japanese Laid-Open Patent Application (Kokai) No. 59-213056, there is also known another method in which, when inserting and discharging the cartridge, the pressing force applied by the roller to the cartridge is released with the use of a click spring, and after the insertion of the cartridge, a lever is angularly moved to cause the roller to press against the cartridge, thereby achieving the positioning of the cartridge.
With the cartridge positioning mechanism shown in FIG. 9, the spring force is always applied to the roller which serves to position the cartridge. Therefore, this mechanism has the disadvantage that it is not satisfactory in operability since the force required, when the cartridge is manipulated to be inserted and discharged, is large. Also, another conventional cartridge positioning mechanism is of the type in which the roller is pressed against the cartridge by angularly moving the lever after the insertion of the cartridge. While no large force is required to manipulate the cartridge during insertion and discharge thereof, one additional step is needed during both the positioning of the cartridge and the discharge thereof, which is not desirable from a viewpoint of operability.
The present invention overcomes the above problems, and an object of this invention is to provide a tape cartridge positioning mechanism which is operable in response to the inserting and discharging operations of the cartridge, respectively, to press the rollers against the cartridge and to release the pressing force to thereby enable the insertion and discharge of the cartridge with a small force, and which accurately positions the cartridge by merely inserting the cartridge, thereby improving the operability.